Hemodialysis or Peritoneal Dialysis?

Kidney failure: If the body's detoxification organs fail, dialysis saves life. But when should patients start using it?

They regulate the mineral balance, help to adjust blood pressure, and produce a hormone that stimulates the formation of red blood cells. Above all, however, the kidneys are a kind of purification plant in the body. They bring back what he needs and eliminate the useless.

"All of these functions decrease in the course of chronic kidney disease," says Professor Andreas Kribben, President of the German Society for Nephrology. The symptoms of the disease are correspondingly diverse. They range from anemia to cardiac arrhythmias to symptoms of intoxication.

Most patients die of cardiovascular diseases, followed by infections, because the immune system also suffers as a result of weak kidneys.

Machine as a lifesaver

At least the cleaning job of the organs has been done by a machine since the 1950s.The dialysis machine is sometimes vital as long as no donor kidney is available. But it is still not clear when patients should start dialysis. This is actually a good way of determining the efficiency of the kidneys.

The measure for this is the glomerular filtration rate (GFR). Glomeruli are clusters of tiny vessels in which blood is filtered and urine is produced. Each kidney has about a million of them.

It makes no sense to start early

Healthy kidneys in young people filter at least 90 milliliters of blood per minute. A GFR of less than 15 is considered to be the end-stage of chronic kidney disease. This is measured, among other things, on the basis of the creatinine content of the blood. This breakdown product of a muscle protein actually has no place in the body; a healthy kidney excretes it in the urine.

If the GFR is reduced, it can no longer do it well. The opposite is true for the protein albumin. It should stay in the body. If it is increasingly found in the urine, this also indicates kidney damage - and the risk of faster progression.

Around 1500 liters of blood flow through the kidneys every day. They pass on 0.5 to two liters of liquid to the bladder

Need dialysis

However, the necessity of dialysis cannot be determined from any of the values. This was shown by a study in 2012 that compared two GFR ranges. Half of the participants should start the blood wash at a value of 10 to 14, the other half only at a value of 5 to 7. Result: An early start neither increased the life span, nor did it reduce the frequency of complications.

However, the majority of the study participants did not start according to the prescribed plan - but when the symptoms suggested it to them. Dr. Matthias Schaier, Senior Physician at the Kidney Center in Heidelberg: "The main criterion is urine poisoning with symptoms such as nausea, vomiting, and aversion to food.

Fatigue and low performance

The GFR has then often dropped to 6 or 7, the patients are increasingly tired, mental performance declines, and blood pressure can no longer be adjusted well. However, there are also cases where the start is made earlier: especially when there is severe water retention in the tissue and lungs and when the potassium level can no longer be controlled.

Nevertheless, the GFR value has an important function for Schaier: If it falls below 30, the time has come when patients should receive intensive advice from a nephrologist.

Diabetes and high blood pressure as the main causes

The kidney disease specialist can provide information about the various dialysis procedures and organ transplantation. Some patients are lucky enough to receive a donor kidney even before dialysis. It would be even better if the course could be slowed down beforehand.

The main causes of kidney failure in developed countries are diabetes and high blood pressure. Both ailments destroy the organ's fine blood vessels. Blood sugar and blood pressure should be well controlled and smoking should be given up. Further treatments are recommended depending on the symptoms.

The benefits of drugs from the group of ACE inhibitors have been well documented. Conversely, you should avoid drugs that are harmful to the kidneys. These include pain relievers such as ibuprofen and diclofenac, as well as some antibiotics.

Which procedure to choose?

However, even with the best therapy, the time to kidney failure can often only be delayed. "Anyone who then decides to have dialysis shouldn't consider it a defeat," emphasizes nephrologist Andreas Kribben. "Many patients tell us that the treatment makes them fit again and that they feel better."

But which dialysis method should you choose? One of the options is hemodialysis, in which the blood is cleaned in a machine. To do this, patients generally come to a center three times a week for four to five hours. An alternative is peritoneal dialysis, in which the body's own peritoneum acts as a filter. The fluid bags have to be changed several times a day and allow blood to be washed around the clock.

Change for your own benefit

From a medical point of view, peritoneal dialysis is more effective in the first few years. But after about five years it will be overtaken by hemodialysis. Then the peritoneum increasingly scarred and can perceive its filter function less and less. So if you always want the best method in each case, you have to be ready to change after a certain time.

However, only about five percent of the currently estimated 85,000 dialysis patients in Germany choose peritoneal dialysis at all. It offers many advantages: It can be better integrated into everyday life, and you don't have to pay so much attention to your diet.

Dialysis procedure

Both can be done in a center or at home. Only around 500 patients in Germany perform hemodialysis at home. The application requires intensive training and sufficient space in the apartment.

Many patients do peritoneal dialysis independently; they only see a doctor every five to six weeks. Older patients in particular appreciate the fact that they are constantly monitored and that the appointments offer a change in the centers.

However, it has certain hygiene requirements. And some patients feel overwhelmed with the procedure without help. The procedure is also less suitable if the peritoneum is scarred from surgery or if the patient suffers from chronic bowel inflammation.

Often companions until death

Sometimes dialysis is only needed temporarily. For example, when the kidneys weakened due to inflammation and recover again. For most patients, however, blood washing remains a companion for the rest of their lives. Unless they are among the few on the waiting list for whom a suitable replacement organ becomes available. Many people are currently waiting for a transplant for more than ten years.